U.S. patent number 5,265,311 [Application Number 07/809,383] was granted by the patent office on 1993-11-30 for self closing hinge.
This patent grant is currently assigned to Econo Max Manufacturing. Invention is credited to E. Scott Gard.
United States Patent |
5,265,311 |
Gard |
November 30, 1993 |
Self closing hinge
Abstract
For swingably mounting a door on a jamb, a dual action self
closing hinge has a stationary component which seals, shields, and
carries a stationary cam and a rotatable cam follower. The cam
elements cooperate with one another to displace the cam follower
and attached door panel upwardly during an opening movement and
permit the automatic downward movement of the cam follower and door
panel upon release of the door panel from an open position.
Simultaneous with the cam action, an offset hinge mechanism
elevates the center of gravity of the door panel during opening,
and likewise provides for the automatic return of the door panel to
the closed position to improve the self-closing action of the door.
In addition, a cam angular position lock enables the closed
position of the door relative to the jamb to be easily
adjusted.
Inventors: |
Gard; E. Scott (Portland,
OR) |
Assignee: |
Econo Max Manufacturing
(Portland, OR)
|
Family
ID: |
25201219 |
Appl.
No.: |
07/809,383 |
Filed: |
December 16, 1991 |
Current U.S.
Class: |
16/312; 16/311;
16/318 |
Current CPC
Class: |
E05F
1/06 (20130101); E05F 1/063 (20130101); E05F
1/068 (20130101); Y10T 16/5395 (20150115); Y10T
16/5398 (20150115); Y10T 16/53996 (20150115); E05Y
2900/132 (20130101) |
Current International
Class: |
E05F
1/06 (20060101); E05F 1/00 (20060101); E05F
001/02 () |
Field of
Search: |
;16/312,311,313,315,316,317,318,310,309,362,364,367,368,378 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Larson; Lowell A.
Assistant Examiner: McKeon; Michael J.
Attorney, Agent or Firm: Klarquist, Sparkman, Campbell,
Leigh & Whinston
Claims
I claim:
1. A self closing door hinge for adjusting a closed door position
of an upright door panel relative to a door jamb, the hinge
comprising:
a door receiving axle assembly for receiving a portion of the door
panel, the axle assembly having a downwardly projecting axle with a
lower end which terminates in a cam follower having a first
inclined cam surface;
a door jamb mounting assembly for mounting the hinge to the door
jamb, the mounting assembly having a body with a chamber which
defines a first axis formed therein and a cam with a second
inclined cam surface, the cam being positioned within the chamber
for pivoting movement about the first axis, with the chamber
pivotally receiving the axle and the cam being pivotal in the
chamber about the first axis while the axle is within the chamber
so as to permit the angular adjustment of the cam surface about the
first axis;
the first and second inclined cam surfaces being alignable in a
face-to-face relationship when the door panel is at rest in a
closed position;
a cam lock for selectively fixing the cam and thereby the cam
surface at a desired angular position about the first axis and with
respect to the door jamb to adjust the closed position of the door
panel;
wherein the door receiving axle assembly further includes:
a door mounting member for receiving a lower portion of the door
panel, with the door mounting member having a lower wall with an
axle hole extending therethrough;
an axle assembly comprising an upper portion from which the axle is
suspended, with the upper portion cooperating with the door
mounting member with the axle extending through the axle hole;
and
a cam follower member having a lower portion terminating in the
first inclined cam surface, and an upper portion for fixedly
receiving the axle therein.
2. A self closing door hinge for adjusting a closed door position
of an upright door panel relative to a door jamb, the hinge
comprising:
a door receiving axle assembly for receiving a portion of the door
panel, the axle assembly having a downwardly projecting axle with a
lower end which terminates in a cam follower having a first
inclined cam surface;
a door jamb mounting assembly for mounting the hinge to the door
jamb, the mounting assembly having a body with a chamber which
defines a first axis formed therein and a cam with a second
inclined cam surface, the cam being positioned within the chamber
for pivoting movement about the first axis, with the chamber
pivotally receiving the axle and the cam being pivotal in the
chamber about the first axis while the axle is within the chamber
so as to permit the angular adjustment of the cam surface about the
first axis;
the first and second inclined cam surfaces being alignable in a
face-to-face relationship when the door panel is at rest in a
closed position;
a cam lock for selectively fixing the cam and thereby the cam
surface at a desired angular position about the first axis and with
respect to the door jamb to adjust the closed position of the door
panel;
wherein the body of the door jamb mounting assembly comprises:
a jamb guard for mounting to an upright portion of the door jamb,
the jamb guard having an outer wall defining a portion of the
chamber; and
a floor plate for mounting to a floor portion of a doorway defined
by the door jamb, the floor plate cooperating with the jamb guard
to define the chamber, the floor plate extending outwardly beyond
the jamb guard to provide a mounting flange for use in mounting the
door jamb mounting assembly to the floor.
3. A self closing door hinge according to claim 2 wherein the jamb
guard has a threaded hole extending through the outer wall to the
chamber; and
the cam lock comprises a threaded locking member threadably
engaging the threaded hole through the jamb guard and selectively
engaging the cam.
4. A self-closing door hinge for adjusting a closed door position
of an upright door panel relative to a door jamb, the hinge
comprising:
a door receiving axle assembly for receiving a portion of the door
panel, the axle assembly comprising a first U-shaped bracket for
mounting to an edge of the door panel, the U-shaped bracket having
first and second flanges between which the edge of a door panel is
disposed and a base plate interconnecting the first and second
flanges, the base plate having an axle receiving opening
therethrough, the axle assembly also including an axle support
plate and an axle mounted to an axle support plate, the axle having
a free end projecting from the axle support plate, the axle being
sized for insertion through the axle receiving opening, the axle
support plate being sized for positioning between the first and
second flanges and against the base plate such that the free end
portion of the axle projects through the axle receiving opening and
from the base plate and defines a first axis, the axle assembly
also including a cam follower mounted to the projecting free end
portion of the axle, the cam follower having a first inclined cam
surface at a lower end thereof, the cam follower being mounted to
the axle for pivoting about the first axis with the pivoting
movement of the door between open and closed positions;
a door jamb mounting assembly for mounting the hinge to the door
jamb, the mounting assembly having a body with a chamber formed
therein and a cam with a second inclined cam surface, the cam being
positioned within the chamber, the chamber also pivotally receiving
the cam follower such that the cam follower is pivotal about the
first axis within the chamber with the movement of the door, the
cam being pivotally received in the chamber for movement about the
first axis while the axle is within the chamber so as to permit the
angular adjustment of the cam surface about the first axis;
the first and second inclined cam surfaces being alignable in a
face-to-face relationship when the door panel is at rest in a
closed position; and
a cam lock for selectively fixing the cam and thereby the cam
surface at a desired angular position about the first axis and with
respect to the door jamb to adjust the closed position of the door
panel.
5. A self closing door hinge according to claim 4 wherein the body
of the door jamb mounting assembly comprises:
a jamb guard for mounting to an upright portion of the door jamb,
the jamb guard having an outer wall defining a portion of the
chamber; and
a floor plate for mounting to a floor portion of a doorway defined
by the door jamb, the floor plate cooperating with the jamb guard
to define the chamber, the floor plate extending outwardly beyond
the jamb guard to provide a mounting flange for use in mounting the
door jamb mounting assembly to the floor.
6. A self closing door hinge according to claim 5 wherein the jamb
guard has a threaded hole extending through the outer wall to the
chamber; and
the cam lock comprises a threaded locking member threadably
engaging the threaded hole through the jamb guard and selectively
engaging the cam.
7. An apparatus according to claim 4 including first and second
hinge assemblies for pivotally coupling respective upper and lower
portions of the door panel to a door jamb, at least one of the
hinge assemblies comprising a hinge of claim 4, the first and
second hinge assemblies being aligned to pivot the door panel about
a tilted axis so as to elevate the center of gravity of the door
panel when opened above the center of gravity of the door panel
when the door panel is closed.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to door hinges, and more
particularly to gravity activated, self closing door hinges. Such
hinges may be used in high traffic, restaurant kitchen swing doors
requiring a full range of swing to both sides of the door frame,
and in refrigerator doors requiring a range of motion to only one
side of the door frame.
A typical gravity activated, self closing door hinge has a door
jamb mounting structure and a pivot post for supporting a door
panel. The hinge also has a complementary cam arrangement coupling
the jamb mounting structure and the pivot post together in a manner
which biases the door panel to a closed position. When closed, the
weight of the door panel is transferred through the pivot post to
the interface of the complementary cam faces to maintain contact
between the cam faces. When the door is opened, an upper rotatable
cam face slides across a lower fixed cam face, resulting in the
upper cam, pivot post, and door panel being elevated above the
closed position. When released from an open position, the weight of
the door panel causes the upper cam to pivot and drop back to the
stable lower position where the door is closed.
These earlier self closing hinges are exposed to potential abuse
when mounted on doors in high traffic areas, and many designs
cannot withstand this abuse. For example, U.S. Pat. No. 3,733,650
to Douglas teaches a lift-off gravity hinge mechanism with
complementary cam members enclosed in a barrel member for use in
exterior gate hinges rather than interior door hinges. When the
Douglas hinge is opened, the hinge pin is elevated by the
cooperating action of the cams. The Douglas hinge is dissembled by
lifting the hinge pin out of the lower barrel. Thus, repeated
jarrings by heavy objects passing through doors suspended by
Douglas hinges may cause dislocation or even complete disassembly
during service. This undesirable trait of Douglas represents at
least a nuisance, if not a danger of injury.
Another self closing hinge is disclosed in U.S. Pat. No. 3,378,881
to Hentzi. Hentzi teaches a restaurant kitchen style gravity
actuated pivot hinge with exposed complementary cam elements
carried by a coaxial pivot pin. Upon rotation, the resultant cam
action of the Hentzi hinge causes the upper cam to elevate. Under
hostile conditions, the Hentzi hinge is vulnerable to damage due to
the exposed nature of Hentzi's cam arrangement. The impact of a
heavy object on the exposed cam could cause imbalance or damage the
cam faces, resulting in a rapid degradation of the hinge. The
closing speed of Hentzi's door may be too slow for some
applications because the cam mechanism is the sole provider of the
closing force.
The possibility of cam damage is minimized in the hinges of U.S.
Pat. Nos. 4,631,777 to Takimoto, and 4,030,161 to Loikitz, which
teach the shielding and sealing of the cam area. These hinges,
however, are undesirable for use in a two way traffic door because
they are not designed to enable a door panel to swing to both sides
of a door frame. The Takimoto and Loikitz hinges apparently reach
the closed position when the door panel contacts the door frame,
and thus, neither provides for any closed door position
adjustment.
Thus, a need exists for an improved gravity activated, self closing
door hinge which is directed toward overcoming, and not susceptible
to, the above limitations and disadvantages.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a self
closing door hinge is provided for adjusting a closed door position
of a door panel relative to a door jamb. The hinge includes a door
receiving axle assembly for receiving a portion of the door panel.
The axle assembly has a projecting axle that terminates in a cam
follower having a first inclined cam surface. The hinge also has a
door jamb mounting assembly for mounting the hinge to the door
jamb. The mounting assembly has a body with a chamber formed
therein and a cam with a second inclined cam surface within the
chamber. The chamber pivotally receives the axle for pivotal motion
about a first axis. The first and second inclined cam surfaces are
alignable in a face-to-face relationship when the door panel is at
rest in a closed position. The hinge also has a cam lock for fixing
a predetermined angular position of the cam about the first axis
with respect to the door jamb to adjust the closed position of the
door panel.
According to another aspect of the invention, a gravity activated
hinge system is provided for suspending and automatically closing a
door panel having a center of gravity within a door jamb. The hinge
system has a lower hinge assembly for pivotally coupling a lower
portion of the door panel with a lower portion of the door jamb.
The hinge system also has an upper hinge assembly for pivotally
coupling an upper portion of the door panel with an upper portion
of the door jamb. The upper and lower hinge assemblies may be
aligned to pivot the door panel about a tilted axis to elevate the
center of gravity of the door panel when opened above a resting
point defined when the door panel is closed.
An overall object of the present invention is to provide for a dual
action self closing hinge which has an extended service life and a
closing action with improved speed and precision.
Another object of the present invention is to provide a rugged
hinge which maintains its structural integrity and smooth closing
action even when the door panel or hinge are exposed to physical
impacts.
An additional object of the present invention is to provide a hinge
with a sealed cam arrangement which is shielded from dust and other
contaminants.
A further object of the present invention is to provide a hinge
which may be installed on either the left or the right side of a
door frame, and which enables a full range of opening and closing
movement to either side of the door frame.
Yet another object of the present invention is to provide a hinge
which facilitates installation and rotational adjustment of the
closed position of a door panel relative to the door frame.
Still another object of the present invention is to provide a hinge
having a rotational adjustment system for adjusting the closed
position of a door panel relative to the door frame, with the
rotational adjustment system being substantially impervious to
inadvertent adjustment and physical abuse.
The present invention relates the above features and objects
individually as well as collectively. These and other objects,
features and advantages of the present invention will become
apparent to those skilled in the art from the following description
and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary front elevational view of one form of an
offset hinge mechanism of the present invention shown mounting a
swinging door on a door jamb;
FIG. 2 is a fragmentary elevational view of the mechanism of FIG. 1
with the door shown in an open position;
FIG. 3 is an enlarged perspective view of the lower hinge of FIG.
1;
FIG. 4 is an exploded perspective view of the lower hinge of FIG.
3;
FIG. 5 is an enlarged elevational view of one form of a cam lock of
the present invention taken along lines 5--5 of FIG. 4;
FIG. 6 is a sectional view taken along lines 6--6 of FIG. 1;
FIG. 7 is an enlarged partially sectional view taken along lines
7--7 of FIG. 6; and
FIG. 8 is a partial sectional view of the lower hinge of FIG. 7
shown with the door panel in an open position.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIGS. 1-2, a gravity activated hinge system 10
constructed in accordance with the present invention is shown
pivotally suspending a door panel 12 from a door jamb or frame 14.
The door frame 14 defines a doorway 15 through a wall 16 and across
a floor portion 18 of the door frame. The hinge system 10 includes
an upper hinge assembly 20 for pivotally coupling an upper portion
22 of the door panel 12 with an upper portion 24 of the door jamb
14. In the illustrated embodiment, the upper hinge assembly 20
includes an L-shaped jamb mounting member or corner mounting
bracket 25. The bracket 25 may be mounted at an upper corner 26 of
the door frame 14 by conventional mounting means, such as lag
screws 28a and 28b.
A pivot post 30 extends downwardly from a horizontal portion 32 of
the corner mounting bracket 25. The pivot post 30 is received
within a pivot post bushing member 34 recessed within the door
panel upper portion 22. The bushing member 34 a depth sufficient to
allow the door panel 12 to elevate during the opening of the door
as described further below. To prevent excessive wear to the door
panel and to add structural integrity and strength to the hinge
system, the upper hinge assembly 20 includes a door panel receiving
portion, such as a U-shaped panel receiving member or bracket 36.
The U-shaped bracket 36 surrounds a portion of the door panel 12
and may be secured to the panel by conventional means, such as bolt
and nut assemblies 38a and 38b.
The hinge system 10 also includes a lower hinge assembly 40 for
pivotally coupling a lower portion 42 of the door panel 12 with a
lower corner 44 of the door jamb 14. In the illustrated embodiment,
the lower hinge assembly 40 includes a door jamb mounting assembly
45 which may be secured to the lower corner 44 by conventional
means, such as two pairs of lag screws 46a, 46b and 48a, 48b (see
FIG. 6) extending into the floor 18 and an upright portion of the
door jamb 14, respectively. The lower hinge assembly 40 also
includes a door receiving axle assembly 50 having a door panel
receiving or mounting member, such as a U-shaped bracket 52. The
door mounting bracket 52 may be secured to the door panel lower
portion 42 by conventional means, such as bolt and nut assemblies
54a and 54b. The assembly 50 also has an axle assembly 55 extending
downwardly from bracket 52. The axle assembly 55 is pivotally
received within the door jamb mounting assembly 45 for pivoting
about a first axis A.
The pivot post 30 is located to pivot the door panel 12 about a
second pivot axis B. The second pivot axis B is offset from the
first pivot axis A by a distance D1 in a direction toward a central
portion of the doorway 15. For example, a two inch offset distance
D1 on a typical grocery store stock room door provides an
approximate 11/8 inch lift to the distal edge of the door panel
opposite the hinged edge. Depending upon the door panel width and
weight, as well as the offset distance D1, distal edge lifts
ranging from 5/8 to 11/2 inches, more or less, are believed to
beneficially assist in gravity closing of the door panel.
As shown in FIG. 2, the offset nature of the first and second pivot
axes A and B causes the door panel 12 to rotate about a
non-vertical, inclined or tilted axis T. The bushing member 34 has
a diameter with sufficient clearance to accommodate the pivot post
30 and allow the door to freely open as panel 12 rotates about the
axis T. The door panel 12 has a center of gravity C located as
shown in FIG. 1 when the door is closed or at rest position (FIG.
1). Opening the door by rotation about axis T elevates the center
of gravity to the position C' when in an open position as shown in
FIG. 2. Opening the door further than the 90.degree.-open position
of FIG. 2, where the door is rotated 90.degree. from a plane
defined by the door panel when closed and centered within the frame
14, provides for even greater elevation of this center of
gravity.
In the illustrated embodiment, the elevational travel of the center
of gravity between the 90.degree.-open and closed positions is
shown as distance D2 in FIG. 2. When the door is opened, the
potential energy of the door panel 12 increases. Upon release, this
increased potential energy translates into kinetic energy as the
open door swings back to the closed position under the influence of
gravity. This kinetic energy is greater than that achieved with a
conventional vertical swing axis. Due to the construction of the
illustrated lower hinge assembly 40, discussed in further detail
below, the distance D2 is further enhanced over the elevational
distance which may be achieved by only offsetting the first and
second pivot axes A and B.
Referring to FIGS. 3 and 4, the lower axle assembly 40 is shown in
greater detail. The U-shaped door mounting bracket 52 has a lower
wall 56 with an axle receiving hole 58 extending therethrough. The
axle assembly 55 includes an axle 60 supported by an axle support
member 62 in a generally T-shaped configuration. The axle support
62 rests against the lower wall 56 and between upright walls 64 and
66 of bracket 52. The axle support 62 may be welded or otherwise
secured to the bracket 52, with the axle 60 extending downwardly
through the axle hole 58.
The axle assembly 55 also includes a cam follower member 70 which
may be of a machinable injection molded plastic, such as nylon or
the like. The cam follower 70 has a hollow bore or socket 72
extending partially therethrough which is sized to receive the axle
60. The cam follower may be secured to the axle 60 by means of a
securing member, such as a set screw 74. The set screw 74 extends
through hole 76 in the cam follower 70 and into hole 78 within the
axle 60. As better shown in FIG. 2, the cam follower 70 includes a
first inclined cam surface 80. Thus, with the axle 60 secured
within the cam follower bore 72, the axle assembly 55 terminates
with the downwardly extending inclined cam surface 80.
The door jamb mounting assembly 45 has a body 82 including a jamb
guard member 84. The jamb guard 84 has an upright portion 85
forming flanges for mounting the guard to an upright portion 86 of
the door jamb 14. The lag screw 48a and 48b (see FIG. 6) extend
through holes, such as hole 88, extending through the flanges of
the upright portion 85. Depending upon the particular application,
the jamb guard 84 may be around three inches high as shown in the
drawings, or substantially taller, for instance, on the order of
nine to twelve inches high. These taller jamb guards (not shown)
are particularly useful for harsh environments, such as for
mounting doors through which forklifts regularly pass.
The body 82 may also include an optional floor plate member 90
which is secured to a lower portion of the jamb guard 84, for
example using screws 92a and 92b. The screws 92a and 92b extend
through holes 94a and 94b within the floor plate 90 and into
threaded holes (not shown) within the jamb guard 84. The floor
plate 92 has two floor mounting holes 95a and 95b for receiving the
respective lag screws 46a and 46b (see FIG. 6). An outer wall
portion 96 of the jamb guard 84 cooperates with the floor 18, or
with the floor plate 90 if used, to define a cam and cam follower
receiving chamber 98 within the body 82.
The door jamb mounting assembly 45 also includes a cam member 100
which is received within chamber 98. The cam 100 has an upright
vertical surface 102 sized to be slidably and pivotally or
rotatably received within chamber 98. The cam 100 may rotate within
chamber 98 as indicated by arrow 104 in FIG. 4. The cam 100
includes a second inclined cam surface 105 configured to be
alignable with the cam follower surface 80 in complimentary
contact, such as a face-to-face relationship (see FIG. 7), when the
door is closed. The upright wall 102 of the cam 100 includes a
lower locking portion 106 located beneath the cam surface 105. The
cam 100 has a lower surface 108 which rests against the floor 18 or
floor plate 90 when the cam 100 is seated within chamber 98.
The lower hinge 40 has a cam lock including a locking member, such
as an externally threaded set screw 110, for selectively coupling
the cam 100 with respect to body 82 to fix the cam 100 at a
predetermined angular position about axis A. The jamb guard 84 has
a threaded hole 112 extending therethrough from an outer surface
114 of the jamb guard to the chamber 98. The cam lock 110 extends
through hole 112. The threaded hole 112 is spaced above a lower
surface 116 of the jamb guard 84 so the cam lock 110 engages the
cam lower locking portion 106 at a predetermined level spaced apart
from the second inclined cam surface 105. As shown in FIG. 5, the
cam lock 110 terminates in a roughened surface 118, which may be
roughened by knurling or the like, to provide a secure frictional
fit against the cam locking portion 106. Thus, during use the cam
lock roughened surface 118 is prevented from intersecting and
damaging the cam surface 105.
As shown in FIG. 6, the closed or at rest position of the door
panel 12 may be adjusted with respect to the door frame 14 by
rotation of the cam 100 within chamber 98 as indicated by arrow
104. Often during the initial installation or during use, the door
panel 12 becomes positioned out of alignment with the door frame
14, such as indicated at position 12' or position 12".
A method of realigning the unaligned or ajar door panel to a
centered or desired position 120 may be preformed by first
disengaging the cam lock 110 by loosening the set screw. As a
second step, the door panel 12 is shifted or rotated to position
120, causing cam follower 70 to rotate the cam 100 about axis A due
to the face-to-face complementary alignment of the inclined cam
surfaces 80 and 105. In a final step, the cam lock 110 is
re-engaged by retightening the set screw so the roughened surface
118 grips the cam locking portion 106 to secure the cam 100 in an
angular position with respect to body 82.
FIGS. 7 and 8 illustrate the enhancing action of the inclined cam
surfaces 80 and 105 to elevate the door panel center of gravity C
through the distance D2 (see FIG. 2). In FIG. 7, the door panel 12
is shown at rest with the cam faces 80 and 105 aligned in
complimentary face-to-face relationship. This closed position
corresponds to the lowest level of potential energy of the door
panel 12. In FIG. 8, the door panel 12 is shown in a
90.degree.-open position to allow passage through doorway 15. The
inclined nature of the cam surfaces 80 and 105 are shown to elevate
the door panel 12 a distance D3, which is less than the distance D2
of FIG. 2. That is, D2 also includes the elevation of the center of
gravity due to the tilted axis T provided by the offset nature of
the upper and lower hinge assemblies 20 and 40.
As shown in FIGS. 2 and 8, when the door is open, the cam faces 80
and 105 are no longer aligned, and the cam follower 70 has ridden
upwardly along surface 105 of the cam 100. This provides for the
additional D3 distance of lift, and an increase in the potential
energy, of the door panel of the door panel 12 above that obtained
through the use of the tilted axis T alone. When released from an
open position, the door panel 12 automatically returns to the
closed position of FIGS. 1 and 7 under the influence of
gravity.
It is apparent that the hinge assembly 40, including the cam lock
110, may be used with a conventionally aligned (non-offset) hinge
(not shown) coupling the door panel upper portion 22 to the frame
14. That is, the adjustable feature of hinge assembly, best shown
in FIG. 6, may be implemented with a door panel pivoting about a
substantially vertical pivot axis (not shown) rather than the
tilted axis T.
In operation, as illustrated in FIG. 2, rotation about the tilted
axis T tilts the door panel 12 at an angle as the door is rotated
in either direction from the closed position, thereby elevating the
center of gravity C of the door panel. When the door panel is
released from such an open position, the door automatic rotates
back about the tilted axis T under the influence of gravity. This
automatic closing action drops the door panel center of gravity C
to the original stable position when the door rests in the closed
position. By itself, the offset nature of the hinge system 10
provides for smooth, automatic closing of the door panel 12.
While the offset nature alone of the hinge mechanism provides a
self closing hinge suitable for most applications, the addition of
a cam mechanism provides for superior automatic closing action. In
the illustrated embodiment, upon the rotation of the door panel
from the closed position, the cam action works in tandem with the
offset nature of the hinge system 10 to elevate the door panel 12
and provide a self-closing action superior to hinge systems
utilizing only a cam mechanism. To provide for a long service life,
as well as smooth operation, the cam and the cam follower surfaces
may be of hard materials with a low coefficient of friction
therebetween. Furthermore, by locking the cam 100 in a desired
angular position with respect to the first axis A, the closed
position of a door panel 12 may be selected as desired.
As described in the foregoing, the self-closing door hinge
according to the present invention has many advantageous
characteristics. One major advantage is represented by the cam
angular position locking system which allows for the easy
adjustment of the closed door position. Thus, the hinge system 10
is ideal for the retrofitting existing doorways. The flexibility of
the closed position adjustment results in the hinge system 10 being
easily adapted to existing non-square door frames. Thus, hinge
system 10 may be used on such imperfect door frames without the
need for laboriously squaring the frame prior to hanging the
door.
Another important advantage of the illustrated embodiment arises
from the superior closing action of the dual action hinge. The
cumulative gravity induced closing forces of the cam arrangement
when combined with the offset hinges result in a significant
improvement in the closing time of the door. This shorter closing
time accommodates a higher volume of two way traffic through
doorway 15 than is obtainable with conventional hinge systems.
Moreover, this improved closing time minimizes the perception of
activities and noise occurring on the opposite side of a door, as
in the case of a bustling, noisy kitchen preparing food in a quiet
restaurant.
The hinge system 10 has an increased service life due to the smooth
hinge operation. This service life is extended by substantially
isolating the hinge components from exposure to debris causing wear
and resulting functional degradation. Thus, the time between
required changes of worn cam elements will be significantly
increased.
Yet another advantage of this invention is the improved durability
of the lower hinge assembly 40 provided by the extensive shielding
of the jamb guard 84. The simple, heavily shielded design of the
lower hinge assembly 40 results in the cam mechanism being
substantially invulnerable to even severe impacts. Likewise, the
heavy shielding and rugged design of the cam lock 110 which is
substantially flush with the outer wall 114 of the jamb guard,
protects the cam lock 110 from impact-induced loosening or
damage.
Moreover, the positioning of the lower hinge assembly 40 on the
floor 18 at the lower corner of the door frame minimizes the
exposure to serious impacts. Such a floor-hugging orientation is
usually only exposed to minor impacts from the rubber wheels of
vehicles passing through the door, rather than serious impacts from
the heavy metal frames of the same vehicles, which usually ride
above the wheels. This minimization of severe impacts further
enhances the service life of the hinge system 10.
Yet another advantage of this invention is the design of the jamb
guard 84, which substantially seals the cam mechanism from the
outside environment. This sealing prevents dust and other
contaminants from reaching the cam surfaces 80 and 105 of the cam
and the cam follower. Thus, cam surface wear and hinge function
degradation resulting from such contamination is substantially
avoided. This freedom from cam element contamination improves the
service life of the hinge.
Finally, unlike many other self closing hinges, the hinge system 10
allows a full range of door motion toward both sides of the plane
of the door frame, while retaining the self closing action. This
range of motion, as illustrated in FIG. 6, can reach at least
90.degree. on either side of the plane of the door frame, and still
close the door panel 12 automatically. Therefore, hinges of this
embodiment will maintain their function even when vehicles of a
width approaching that of the door frame pass in either direction
through the door.
Having illustrated and described the principles of my invention
with respect to a preferred embodiment, it should be apparent to
those skilled in the art that my invention may be modified in
arrangement and detail without departing from such principles. For
example, other types of upper hinge assemblies may be used to pivot
the door panel upper portion 22. Furthermore, other types of
conventional door attachment means may be used which are known to
be interchangeable by those skilled in the art and may be
substituted herein. I claim all such modifications falling with the
scope and spirit of the following claims.
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